Periodic Reporting for period 4 - PREP-CRYPTO (Preparing Cryptography for Modern Applications)
Berichtszeitraum: 2021-08-01 bis 2022-06-30
However, the concrete schemes proposed are currently scrutinized for cryptanalytic attacks, and it appears that many of them are considerably less secure than initially hoped for. Moreover, most constructions of new cryptographic building blocks still constitute "possibility results" rather than practically relevant schemes. In fact, while being improved continuously, most existing constructions are still far too inefficient for practical use cases. The goal of this project is to prepare these new building blocks for modern applications. Specifically, we will give new constructions of these new
building blocks that
- are secure in a strong sense,
- have a significantly extended functionality, and
- are efficient when tailored to specific applications.
The technical means to achieve our goals is to combine these new building blocks with well-established algebraic cryptographic tools. For instance, we plan to mesh obfuscation with cyclic groups, in order to obtain more secure and more powerful multilinear maps. Our work prepares the ground for practical real-life applications from new cryptographic building blocks.
We have also gained significant new theoretical insights. For instance, we have shown impossibility results and lower bounds for a number of cryptographic tasks, including functional encryption and tasks which require security against adaptive attacks. Our results also give a partial explanation for the apparent difficulty to construct secure instances of new cryptographic building blocks (like certain types of functional encryption or obfuscation schemes).
Finally, we could also raise the confidence in existing cryptographic schemes. Specifically, we have shown that common idealizations and abstractions used for cryptographic analyses are actually sound and can be achieved. Hence, we believe that our work already has significantly improved our understanding of and confidence in existing and widely deployed cryptographic schemes that rely on such idealizations.
We have published our results at the top venues in cryptography. In total, we have published 27 project-relevant papers, 16 of them at the flagship conferences in cryptography.
From a more practical point of view, we expect that our research yields better cryptographic constructions, and increases our confidence in existing cryptographic schemes. Specifically, we believe that our work already has significantly improved our understanding of and confidence in existing and widely deployed cryptographic schemes. Our work will also yield new methods of protecting computation (as opposed to simply encrypting static data) that are suitable for modern scenarios.